We propose to develop and demonstrate two information systems built around medical decision models. The first aim of this project is to develop and operate an information system to improve access to knowledge about explicit models of medical decision making, Decision Support Technologies (DSTs). This system will be designed to respond to queries from DST developers, clinicians, health care administrators and other professionals. To accomplish this we will implement a many-to-many relational database and maintain it with up-to-date information from the literature and other sources. The other specific aim is to provide medical students with a source of medical knowledge organized around explicit models of decision support and to evaluate the effect their use of this system has on their understanding of medicine and their ability to solve clinical problems. Through these computer-based tools, each student will have easy access to all components of an integrated medical information system, including patient data, interpretations of that data, the logical basis for those interpretations, and the experimental basis for the logic as contained in the medical literature. In addition, the students will learn to build and test their own decision models as a problem solving activity.